I don’t disagree with most of what you’re @Fedor_Torgovnikov. Fronius is definitely not the only game in town, and absolutely Sungrow and Huawei seem like very good inverters.
In answer to why people are buying whole new systems, it’s when their inverters are just out of warranty, and people are being quoted $2.5k + for a replacement. Inverter warranties are longer now than they used to be, and inverter quality is much much improved. I haven’t got a lot of personal insight into Solis to be honest, they do seem to be a decent option.
The reason I am wary is that I’ve been burnt a number of times, and seen many other people burnt, buying inverters that seem to be perfectly decent units, but then start dropping like flies a couple years down the track. Not always Chinese inverters mind you.
Anyway, good insight from you @Fedor_Torgovnikov, thanks.